Turning to the issues first, the difference between the two is strikingly large. As I explained back when Paul ran in 2008, he has very nonlibertarian positions on free trade, school choice, and especially immigration. He also believes that Kelo v. City of New London was correctly decided because he thinks the Bill of Rights does not apply to the states. The latter is theoretically compatible with being a libertarian; one can believe that the Constitution should protect us against various forms of oppression by state governments, but simply fails to do so. But Paul’s position is at odds with most modern research on the original meaning of the Fourteenth Amendment, and with the views of virtually all libertarian constitutional law scholars. It also bodes ill for the nature of his judicial appointments in the unlikely event that he actually wins the presidency.

On all of these issues, Johnson is clearly superior to Paul from a libertarian point of view. He supports school choice and free trade agreements, he’s as pro-immigration as any successful politician can be, and he believes that the Bill of Rights constrains the states as well as the federal government. On the other hand, I can’t think of a single issue where Paul is more libertarian than Johnson, though I’m open to correction by people who know more about their records than I do.[…]Johnson is also probably more politically effective than Paul. That’s because he doesn’t carry any of the negative baggage that Paul does. Unlike Paul, Johnson never published a newsletter with racist and anti-Semitic content, or signed on to a political strategy of appealing to white racial resentment against minorities, as Paul did in the early 1990s. As I said during the 2008 campaign, I don’t believe that Paul is a racist. But his record of insensitivity on racial issues dogged him in 2008, and is likely to resurface in 2012 if his candidacy becomes at all successful. Paul also has a record of endorsing weird right-wing conspiracy theories, such as the mythical “North American Union.” This too was seized on by the media in 2008, and could be a problem again. If Paul becomes the public face of libertarianism in 2012, there is a risk that the movement as a whole could be tainted by association with these dubious elements of his record. By contrast, Johnson has no comparable problems, as far as I know.[…]The big advantages that Paul has over Johnson are that he has more money and greater name recognition. But if libertarian activists, donors, and intellectuals become aware of the ways in which Johnson is the superior candidate, they might rally around him and possibly give his campaign the boost it needs to take off and surpass Paul.

Realistically, neither Johnson nor Paul has a strong chance of actually winning the GOP nomination. But if his campaign gets off the ground, Johnson will have better odds than Paul does because he’s more appealing to voters and the media, and less hated by the GOP establishment. More importantly, he’s certainly a far superior libertarian protest candidate and public face for the movement. The chance that either candidate can win the presidency in 2012 is remote. But Johnson is the one more likely to serve as an effective spokesman for libertarianism, adding new supporters without unnecessarily alienating people.

It’s a big “if” that Johnson’s campaign gets off the ground, and I say that as a supporter of his. There are friends dear to my heart that are supporting and in a couple of cases working for Dr. Paul, so I don’t post this here to jab at them; however, I tend to agree with what Somin is saying here.

The elements of Mr Paul’s past and creed that Mr Somin, Ms Dalmia, and I find objectionable are not really liabilities. They are an important part of what makes “Dr No” a candidate capable of generating surprising amounts of enthusiasm and campaign cash, if not votes. Mr Paul and the tea-party movement are each in their separate ways creatures of Cold War-era conservative-libertarian “fusionism”, which remains a powerful ideological and institutional force on the right. In contrast, Mr Johnson comes off as a post-fusionist, libertarian-leaning fiscal conservative. The very existence of such a creature heartens me, but it remains that there exists in our culture no popular, pre-packaged political identity that celebrates and defines itself in terms of these laudable tendencies.

I have a lot of respect for both men, though I tend to agree with Johnson more than Paul. What I hope for is that those of us that are choosing between the two can do so respectfully and not tear the other down.